Moisture control label

ABSTRACT

Self-adhesive moisture control label for product packaging including a water absorbent layer capable of absorbing water and an adhesive layer provided such that the label can be adhered to the packaging. The moisture control label is capable of controlling the humidity of the atmosphere within the packaging.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/GB2013/053015, filed Nov. 15, 2013, which claims the priority ofGreat Britain Application No. 1300225.8, filed Jan. 7, 2013 and U.S.Provisional Application No. 61/727,482, filed Nov. 16, 2012.

FIELD OF THE INVENTION

The invention relates to a self-adhesive moisture control label forproduct packaging which is capable of controlling the humidity of theatmosphere within the packaging. In particular, although notexclusively, the invention relates to a self-adhesive moisture controllabel which can be used to humidify the atmosphere within productpackaging, such as tobacco packaging, so as to prevent the product, suchas tobacco, from drying out.

BACKGROUND OF THE INVENTION

It may be desirable to control the moisture content (or humidity) of theatmosphere in which perishable products are stored in order to preventthem from deteriorating. Perishable products, such as tobacco and food,are often stored in a sealed container in an attempt to keep them fresh.However, the seal on such containers is never perfect, particularly ifthe containers are disposable. Therefore, over time, the perishableproduct may either dry out, or absorb water and become damp.

For example, in order to prevent tobacco from drying out it is desirableto store it in an atmosphere that is not too dry. In another example, inorder to prevent biscuits from going stale, it is necessary to storethem in an atmosphere that is not too moist.

It is known to place a wet sponge in a cigar case in order to preventthe cigars from drying out. However, this is not appropriate for mostother forms of tobacco, such as loose tobacco, as if the wet spongecomes into contact with the tobacco it may rot the tobacco. It is alsoknown to use sachets of a desiccant material in product packaging inorder to maintain dryness. However, the contents of such sachets can bepoisonous if ingested and therefore may not be suitable for foodproducts or the like.

It is therefore desirable to provide a means for controlling themoisture content of the atmosphere within product packaging.

SUMMARY OF THE INVENTION

According to an aspect of the invention there is provided self-adhesivemoisture control label for product packaging, comprising: a waterabsorbent layer capable of absorbing water; and an adhesive layerprovided such that the label can be adhered to the packaging; whereinthe moisture control label is capable of controlling the humidity of theatmosphere within the packaging. The water absorbent layer may be wettedby a user such that in use water evaporates from the surface so as toprovide moisture (i.e. humidify) the atmosphere within the packaging.The label may therefore be used to prevent a product from drying out. Inanother arrangement, the water absorbent layer may absorb water from theatmosphere to dry (i.e. dehumidify) the atmosphere within the packaging.The label may therefore be used to prevent a product from absorbingwater.

The water absorbed by the water absorbent layer may be able to evaporatefrom the water absorbent layer so as to control the humidity of theatmosphere within the packaging.

The water absorbent layer may comprise a fibrous pad or layer. Thefibrous pad or layer may be woven or non-woven (such as a mat). Thefibrous pad may comprise polymer fibres. The fibrous pad may comprisepolyolefin fibres and/or polyethylene terephthalate (PET) fibres and/orpolyethylene (PE) fibres and/or nylon fibres and/or polyvinyl chloride(PVC) fibres and/or polylactic acid (PLA) fibres. In other embodimentsthe water absorbent layer may comprise cellulose and/or paper and/orcotton. The water absorbent layer may be porous. The water absorbentlayer may comprise a hydrophilic material. The hydrophilic material maycomprise a hydrogel. The water absorbent layer may comprise a spongematerial. The water absorbent layer may be continuous.

The water absorbent layer may only be capable of absorbing less than 10ml, less than 8 ml, less than 6 ml, less than 4 ml, less than 3 ml, lessthan 2 ml or less than 1 ml of water. Further, the water absorbent layermay be capable of absorbing greater than 0 ml, greater than 0.1 ml,greater than 0.2 ml, greater than 0.3 ml, greater than 0.4 ml, orgreater than 0.5 ml of water. The water absorbent layer may be capableof absorbing at least 0.6 ml of water. The water absorbent layer may becapable of absorbing between 0.2-2 ml, 0.3-1.5 ml, 0.4-1 ml or 0.5-0.8ml of water.

The water absorbent layer may have a thickness of less than 5 mm, lessthan 4 mm, less than 3 mm or less than 2 mm. The water absorbent layermay have a thickness of at least 0.1 mm, at least 0.2 mm, at least 0.4mm, at least 0.6 mm, at least 0.8 mm or at least 1 mm. The waterabsorbent layer may have a thickness of between 0.1 mm-5 mm, 0.2 mm-4mm, 0.3 mm-3 mm, 0.5 mm-2 mm, or 0.7 mm-1.8 mm.

The water absorbent layer may have an area (in plan view) of less than100 cm², less than 80 cm², less than 60 cm², less than 40 cm², less than20 cm², less than 10 cm², or less than 8 cm². The water absorbent layermay have an area (in plan view) of greater than 0.1 cm², greater than0.2 cm², greater than 0.5 cm², greater than 1 cm², greater than 1.5 cm²,greater than 2 cm², greater than 3 cm², greater than 4 cm², greater than5 cm², greater than 6 cm², or greater than 7 cm². The water absorbentlayer may have an area (in plan view) of between 0.2-20 cm², 0.5-15 cm²,1.5-10 cm², or 3-8 cm².

The water absorbent layer may have a density of less than 1 g/cm³, lessthan 0.9 g/cm³, less than 0.8 g/cm³, less than 0.7 g/cm³, less than 0.6g/cm³, less than 0.5 g/cm³, less than 0.4 g/cm³, less than 0.3 g/cm³, orless than 0.2 g/cm³. The water absorbent layer may have a density ofgreater than 0.01 g/cm³, greater than 0.02 g/cm³, greater than 0.03g/cm³, greater than 0.04 g/cm³, greater than 0.05 g/cm³, greater than0.06 g/cm³, greater than 0.07 g/cm³, greater than 0.08 g/cm³, greaterthan 0.09 g/cm³, or greater than 0.1 g/cm³. The water absorbent layermay have a density of between 0.01-1 g/cm³, 0.02-0.9 g/cm³, 0.03-0.8g/cm³, 0.05-0.7 g/cm³, 0.08-0.5 g/cm³, 0.09-0.3 g/cm³, or 0.1-0.2 g/cm³.

The label may further comprise a base layer to which the water absorbentlayer is adhered to (either directly or indirectly) on a front side. Thebase layer may be a uniform layer of material or may be a laminatestructure. The adhesive layer, which may be continuous or discontinuous,may be provided on the rear side of the base layer. The base layer maybe larger than the water absorbent layer such that a display regionextends beyond the periphery of the water absorbent layer. Useinstructions and/or commercial graphics may be provided on the displayregion of the base layer. The water absorbent layer may be locatedcentrally with respect to the base layer. The base layer and/or thewater absorbent layer may be circular, square, triangular or anysuitable shape. If circular, the base layer and water absorbent layermay be concentric with one another.

The base layer may have a thickness of at least 10 μm, at least 25 μm,at least 50 μm, at least 75 μm or at least 100 μm. The base layer mayhave a thickness of less than 1 mm, less than 0.5 mm, less than 0.25 mm,or less than 0.15 mm. The base layer may have a thickness of between 10μm-1000 μm, 20 μm-700 μm, 50 μm-500 μm, 60-250 μm, or 80 μm-150 μm.

The base layer may comprise polypropylene. The base layer may comprisemono-oriented polypropylene. The base layer may comprise polyethyleneterephthalate (PET), polyethylene (PE) or polyvinyl chloride (PVC).

The water absorbent layer may be adhered to the base layer with apressure sensitive adhesive, for example. The adhesive layer maycomprise a pressure sensitive adhesive.

The opacity of the water absorbent layer may vary as a function of theamount of water retained by the water absorbent layer. In a dry statethe water absorbent layer may have a first (high) opacity and in asaturated state the water absorbent layer may have a second (low)opacity which is lower than the first opacity. In use, a graphicalindicium disposed below the water absorbent layer may become lessvisible as the water absorbent layer becomes drier, and may become morevisible as the water absorbent layer becomes wetter. This may provide auseful indication to the user as to the moisture content of the waterabsorbent layer. A graphical indicium may be provided below the waterabsorbent layer. The graphical indicium may be provided on the baselayer. Alternatively, the graphical indicium may be provided on theproduct packaging or on a separate component. The graphical indicium maybe any suitable graphic such as a logo, text, colour, marking,promotional information, symbol, or sign.

The invention also relates to a plurality of labels, each in accordancewith any statement herein, releasably adhered to a backing sheet.

According to another aspect there is provided a wound reel of labelscomprising a wound backing sheet with a plurality of labels, each inaccordance with any statement herein, releasably adhered to the backingsheet.

According to yet another aspect of the invention there is providedproduct packaging defining a volume for containing a product, wherein aself-adhesive moisture control label in accordance with any statementherein is adhered to the packaging such that the label is disposedwithin the volume so that it can control the humidity of the volume.

The product packaging may be packaging for a tobacco product. Thetobacco product may be loose tobacco or cigars or cigarettes or snuff orsnus. The product packaging may comprise a tub having a container basedefining a volume and a detachably attachable lid, wherein the label isadhered to the inside of the lid.

According to a further aspect of the invention there is provided amethod of manufacturing a wound reel of self-adhesive moisture controllabels for product packaging, comprising: applying an adhesive to therear side of a continuous web of water absorbent material; releasablyadhering the web of water absorbent material to a backing sheet; cuttinga series of discrete water absorbent layers from the web of waterabsorbent material; removing the skeleton (or mask) of the waterabsorbent material; and winding the backing sheet into a reel.

The method may further comprise: applying an adhesive to the rear sideof a continuous web of base material; releasably adhering the web ofbase material to a backing sheet; cutting a series of discrete baselayers from the web of base material; removing the skeleton of the basematerial; and repeatedly removing a discrete water absorbent layer fromits backing sheet and adhering to a discrete base layer to form a seriesof laminate self-adhesive moisture control labels.

It should be appreciated that the method steps may be performed in anysuitable order and are not limited to the order presented herein.

The invention may comprise any combination of the features and/orlimitations referred to herein, except combinations of such features asare mutually exclusive.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example,with reference to the accompanying drawings, in which:

FIG. 1 schematically shows a plan view of a self-adhesive moisturecontrol label;

FIG. 2 schematically shows a cross-sectional view through aself-adhesive moisture control label;

FIG. 3 schematically shows product packaging having a moisture controllabel adhered thereto;

FIG. 4 schematically shows a moisture control label in a wet state; and

FIG. 5 schematically shows a moisture control label in a dry state.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a self-adhesive moisture control label 10 for productpackaging. In this particular embodiment the label 10 is intended to beadhered to product packaging so as to provide moisture to the atmospherewithin the packaging. As will be described in detail below, the label 10comprises a base layer 12 and a water absorbent layer 14 which isadhered to the upper side of the base layer 12. The lower side of thebase layer 12 is provided with an adhesive layer 30 such that the label10 can be adhered to product packaging. In use, a small amount of wateris provided to the water absorbent layer 14 which is absorbed andretained by the water absorbent layer 14. The water retained by thewater absorbent layer 14 is then able to evaporate from the waterabsorbent layer 14 so as to provide moisture to the atmosphere withinthe product packaging. The label 10 therefore acts to humidify thesurrounding atmosphere.

The label 10 is substantially circular and comprises a circular baselayer 12 of a first diameter, and a circular water absorbent layer 14 ofa second diameter that is less than the first diameter. In thisembodiment the diameter of the base layer 12 (and therefore the overalllabel 10) is approximately 50mm and the diameter of the water absorbentlayer 14 is approximately 25 mm. The base layer 12 and water absorbentlayer 14 are concentric with one another and the base layer 12 extendsbeyond the periphery of the water absorbent layer 14 to form a displayregion 15. It should be appreciated that other shapes and dimensionscould be used, and the base layer 12 and water absorbent layer 14 couldbe positioned differently with respect to one another. Although it hasbeen described that the base layer 12 is larger than the water absorbentlayer 14, in other embodiments the layers could be identically sized, orthe base layer 12 could be smaller than the water absorbent layer 14.

As shown in FIG. 2, the base layer 12 is a laminate structure comprisinga lower film 16, a print layer 18 and an upper film 20. The print layer18 is therefore sandwiched between the lower film 16 and the upper film20 which acts as a protective layer. In this embodiment, the lower film16 is a layer of white polypropylene having a thickness of approximately60 μm and the upper film 20 is a layer of clear polypropylene having athickness of approximately 20 μm. It should be appreciated that othermaterials or thicknesses could be used. It should be noted that in otherembodiments the base layer 12 could be a single uniform layer of film.The print layer 18 is directly printed onto the lower film 16 and maycomprise any suitable colours, graphics, designs or text. In thisembodiment the print layer comprises a solid colour which extends overthe entire surface of the lower film 16, branding information 22,instructions for use 24 and a graphical indicium 26. The brandinginformation 22 and the use instructions 24 are printed in the displayregion 15 beyond the water absorbent layer 14, whilst the graphicalindicium 26 is printed in a region underneath the water absorbent layer14. The function of the graphical indicium 26 will be described indetail below. The lower surface of the lower film 16 (and hence thelower surface of the base layer 12) is provided with a layer of pressuresensitive adhesive 30. The adhesive layer 30 may either be a continuousor a discontinuous coating. The adhesive layer 30 allows the label 10 tobe adhered to product packaging. In other embodiments the print layer 18may be separate from the base layer 12.

The water absorbent layer is in the form of a fibrous pad 14 which canabsorb and retain water, and from which water can evaporate. In thisembodiment the fibrous pad 14 is non-woven and is made from mattedpolyolefin fibres. The diameter, thickness and density of the fibrouspad 14 may be chosen such that the fibrous pad can absorb a requiredvolume of water. For example, a polyolefin fibrous pad 14 having a 25 mmdiameter, a thickness of 1.5 mm and a density of between 0.1-0.2 g/cm³may absorb approximately 0.6 ml of water. In another example, apolyolefin fibrous pad 14 having a 31 mm diameter, a thickness of 1 mmand a density of between 0.1-0.2 g/cm³ may absorb approximately 0.6 mlof water. The lower surface of the fibrous pad 14 is provided with alayer of pressure sensitive adhesive 32 which adheres the fibrous pad 14to the upper surface of the upper film 20 of the base layer 12.

The polyolefin fibrous pad 14 permits visible light to pass through it.However, the opacity of the fibrous pad 14 is the function of the amountof water retained by it. In particular, when the fibrous pad 14 iscompletely dry it has a higher opacity, and when it is completelysaturated with water it has a lower opacity. The Applicant believes thatthis phenomena is due to the fibres reflecting light when dry, butallowing light to pass through them when wet. As will be described indetail below, this means that in use, the graphical indicium 26 printedon the base layer 12 becomes less visible as the fibrous pad 14 driesout. This may provide a useful indicator to the use that the fibrous pad14 needs to be wetted.

A particular benefit of the fibrous pad 14 is that it maintains itsintegrity and tends not to fragment. This may be particularly importantas it may be important to prevent fragments of the fibrous pad 14 beingmixed with the product which is contained within the product packaging.

Although it has been described that the water absorbent layer 14 is apolyolefin fibrous pad 14, it should be appreciated that other materialscould be used. The water absorbent layer 14 could be any woven ornon-woven fibrous material and could be made from materials other thanpolyolefin fibres such as polyethylene terephthalate (PET) fibres,polyethylene (PE) fibres, nylon fibres, polyvinyl chloride (PVC) fibres,or polylactic acid (PLA) fibres, for example. In some embodiment thewater absorbent layer may comprise a mixture of polymer fibres, such asany combination of the polymer fibres listed above. Further, the waterabsorbent layer 14 could be a sponge-like porous material capable ofabsorbing water, or could be a hydrophilic material such as a layer of ahydrophilic gel. Essentially, the water absorbent layer 14 could be madefrom any suitable material that is capable of absorbing and retainingwater, and which allows water to subsequently evaporate from it.

Self-adhesive moisture control labels 10 may be provided on a woundbacking sheet as a reel of labels. The labels 10 may then be appliedeither manually, or automatically, or by a combination of the two toproduct packaging.

A reel of moisture control labels 10 may be manufactured by thefollowing method:

A web of lower film material 16 is printed with the desired print layer18 which continually repeats. A web of upper film material 20 is thenapplied over the print layer 18 to provide a protective barrier. Apressure sensitive adhesive layer 30 is then applied to the underside ofthe lower film material 16 and the laminate structure is releasablyadhered to a web of backing material. The individual base layers 12 arethen die cut from the laminate and the skeleton (or mask) is removed.

A web of water absorbent material 14, such as a web of polyolefinfibrous material, is coated on its lower surface with a pressuresensitive adhesive layer 32. This is web is then releasably adhered to aweb of backing material. The individual water absorbent layers 14 (orfibrous pads) are then die cut from the web and the skeleton (or mask)is removed.

The individual base layers 12 and water absorbent layers 14 are thenassembled together to form a moisture control label 10. Specifically, bymachine, the individual water absorbent layers 14 are peeled from thebacking sheet and applied to the upper surface of individual base layers12 which remain on the backing sheet. The backing sheet, having theassembled base layers 12 and water absorbent layers 14, is then wound-upto provide a reel of self-adhesive moisture control labels.

FIG. 3 shows product packaging in the form of a tub 100 for containingloose (or rolling) tobacco. The tub 100 is generally cylindrical andcomprises a container base 102 having a cylindrical wall and a circularbase, and a circular lid 104 which can be removably attached to thecontainer base 102. The loose tobacco is stored within the containerbase 102 and the lid 104 is attached to the container base 102 in orderto close the tub 100. Before the tub 100 has been opened for the firsttime a foil seal (not shown) hermetically seals the container base 102and maintains the freshness of the tobacco. However, once this has beenremoved to obtain access to the tobacco for the first time, the lid 104does not seal the container base 102 to the same extent.

It is desirable to prevent the tobacco from drying out as this canadversely affect its quality. Therefore, a self-adhesive moisturecontrol label 10 is applied to the underside of the lid 104 so that itis disposed within the tub 100 when the lid 104 is attached to thecontainer base 102. The label 10 may be adhered to the lid from a reelof labels 10 during manufacture of the packaging and may be appliedeither by hand, or by machine, or by a combination of the two. Inanother arrangement the label 10 may be disposed within the tub 100 withthe tobacco and the consumer may have to adhere the label 10 to theinside of the lid.

Once tub 100 has been opened by removing the lid 104 and the foil seal(not shown), the consumer must wet the fibrous pad 14 of the label 10.The instructions for use of the label 10, together with brandinginformation, is provided on the display region 15 of the base layer 12which means that it is not necessary to provide any additional insertsor instructions for use. The use instructions 24 may direct the consumerto add a certain amount of water to the fibrous pad 14. In thisembodiment, the consumer is directed to add 6 drops of water to thefibrous pad 14. The lid 104 is then attached to the container base 102with the label 10 disposed within the tub 100. Over time, waterevaporates from the fibrous pad 14 which acts to provide moisture to theatmosphere within the tub 100, humidifying the atmosphere, andpreventing the tobacco from drying out. The label 10 therefore acts tomaintain the quality of the tobacco.

Referring now to FIGS. 4 and 5, as described above, the opacity of thewater absorbent layer 14 (fibrous pad) changes as the volume of waterretained by the fibrous pad 14 changes. In particular, the opacity ofthe fibrous pad 14 increases as the volume of water retained reduces.Therefore, when the fibrous pad 14 is saturated with water (i.e. whenthe consumer has added the prescribed number of drops of water), theopacity of the fibrous pad 14 is relatively low and therefore thegraphical indicium 26 printed on the base layer 12 below the fibrous pad14 is visible through the fibrous pad 14 (FIG. 4). However, as the waterevaporates from the fibrous pad 14 and the fibrous pad 14 becomes drier,the opacity of the fibrous pad increases. Therefore, as the fibrous pad14 becomes drier the graphical indicium 26 becomes less visible, untilthe fibrous pad 14 completely dries out and the graphical indicium 26becomes its least visible (FIG. 5). It should be appreciated that evenwhen dry, the graphical indicium 26 may be partly visible, if feint.

The change in opacity of the fibrous pad 14 in conjunction with thegraphical indicium 26 disposed below it provides a useful indication tothe consumer as to when it is necessary to add more water to the fibrouspad 14 in order to ensure that the atmosphere within the packaging iskept moist. The graphical indicium 26 may be any graphic and may includebranding relating to the product. Although the change in opacity of thewater absorbent layer 14 in conjunction with the graphical indicium 26located below it provides a useful indicator, this is not essential tothe invention. In other embodiments there may be no graphical indicium,and/or the water absorbent layer 14 may not change in opacity as afunction of the water absorbed/retained by it.

In the above embodiment it has been described that the label 10 isapplied to a tub 100 for loose tobacco. However, it should beappreciated that the label 10 could be used with other types ofpackaging for loose tobacco such as pouches. Further, the label 10 maybe used with packaging for other tobacco products such as cigarettes,cigars, snuff or snus. As opposed to being applied to packaging duringmanufacture, the labels 10 may be sold separately to the end-user whomay apply them to various types of packaging or container asappropriate. For example, a label 10 could be applied by an end-user toa tin within which is stored loose tobacco, or a case for storing cigarsor cigarettes.

It has been described that the label 10 is used to prevent tobacco fromdrying out. However, it could be used to prevent other products such asperishable goods, processed foods, fresh foods, plants/flowers,agricultural compounds, seeds, pharmaceuticals, cosmetics, domestic orhousehold chemicals, industrial chemicals, electronic components,instrumentation and devices, clothing or garments, footwear, luggage orbags, stationary or documentation, artwork or photography, jewellery, ormusical instruments from drying out, or becoming too wet (as describedbelow), and spoiling.

Although it has been described that the moisture control label 10 is forproviding moisture to an atmosphere in order to prevent a product, suchas tobacco, from drying out, the label 10 could work in the oppositemanner. For example, the label 10 could be applied to packaging, such asa tin or tub, for biscuits and the water absorbent layer 14 could absorbmoisture from the atmosphere to prevent the biscuits from absorbingwater and becoming soft or stale. In another embodiment the label 10could be adhered to salad packaging, such as a filmic bag, and in usecould absorb water from the salad to prevent it from becoming overlywet.

In another embodiment, the label may simply comprise a self-adhesivewater absorbent layer 14, such as a fibrous pad, which can be adhered toproduct packaging. In such an embodiment the label would comprise thewater absorbent layer 14 and the adhesive 32. The label could be appliedto product packaging over a graphical indicium printed or otherwiseprovided on the packaging itself. As for the first embodiment, the waterabsorbent layer 14 would change in opacity as a function of the waterretained by it and therefore the graphical indicium on the packagingwould become more visible as the label gets wetter, and less visible asthe label gets drier.

Due to the material properties of the fibrous pad, in particular thedensity and substantially uniform structure, the fibrous pad can besaturated with a specific known and reproducible volume of water. Thisallows a fibrous pad to be designed so as to hold a desired volume ofwater which is appropriate to the particular application. This ensuresthat the fibrous pad cannot be overfilled which helps to reduce the riskof damaging the product with which it is to be used.

In some embodiments, the material properties allow a relatively largefibrous pad to be manufactured, which holds a relatively small volume ofwater.

Where the term “layer” has been used in the foregoing specification,this should be understood as encompassing either a continuous ordiscontinuous layer (such as a grid or a series of discrete spots). Forexample, the adhesive layer 30 may be a continuous film of adhesive, orcould be a series of stripes, or a grid, or spots.

1. A self-adhesive moisture control label for product packaging,comprising: a water absorbent layer capable of absorbing water; and anadhesive layer provided such that the label can be adhered to thepackaging; wherein the moisture control label is capable of controllingthe humidity of the atmosphere within the packaging; wherein in use, agraphical indicium disposed below the water absorbent layer becomes lessvisible as the water absorbent layer becomes drier, and becomes morevisible as the water absorbent layer becomes wetter.
 2. A labelaccording to claim 1, wherein water absorbed by the water absorbentlayer can evaporate from the water absorbent layer so as to control thehumidity of the atmosphere within the packaging.
 3. A label according toclaim 1, wherein the water absorbent layer comprises a fibrous pad. 4-6.(canceled)
 7. A label according to claim 1, wherein the water absorbentlayer comprises a sponge material.
 8. A label according to claim 1,further comprising a base layer to which the water absorbent layer isadhered to on a front side, wherein the adhesive layer is provided onthe rear side of the base layer.
 9. A label according to claim 8,wherein the base layer is larger than the water absorbent layer suchthat a display region extends beyond the periphery of the waterabsorbent layer.
 10. A label according to claim 9, wherein useinstructions and/or commercial graphics are provided on the displayregion of the base layer.
 11. A label according to claim 8, wherein thewater absorbent layer is located centrally with respect to the baselayer.
 12. A label according to claim 8, wherein the base layercomprises polypropylene.
 13. (canceled)
 14. A label according to claim8, wherein the water absorbent layer is adhered to the base layer with apressure sensitive adhesive.
 15. A label according to claim 1, whereinthe adhesive layer comprises a pressure sensitive adhesive.
 16. A labelaccording to claim 1, wherein the opacity of the water absorbent layervaries as a function of the amount of water retained by the waterabsorbent layer.
 17. A label according to claim 1, wherein in a drystate the water absorbent layer has a first opacity and wherein in asaturated state the water absorbent layer has a second opacity which islower than the first opacity. 18-28. (canceled)
 29. A plurality oflabels, each in accordance with claim 1, releasably adhered to a backingsheet.
 30. A wound reel of labels comprising a wound backing sheet witha plurality of labels, each in accordance with claim 1, releasablyadhered to the backing sheet.
 31. Product packaging defining a volumefor containing a product, wherein a self-adhesive moisture control labelin accordance with claim 1 is adhered to the packaging such that thelabel is disposed within the volume so that it can control the humidityof the volume.
 32. Product packaging according to claim 31, wherein theproduct packaging is packaging for a tobacco product.
 33. A method ofmanufacturing a wound reel of self-adhesive moisture control labels forproduct packaging, comprising: applying an adhesive to the rear side ofa continuous web of water absorbent material; releasably adhering theweb of water absorbent material to a backing sheet; cutting a series ofdiscrete water absorbent layers from the web of water absorbentmaterial; removing the skeleton of the water absorbent material; andwinding a backing sheet into a reel.
 34. A method according to claim 33,further comprising: applying an adhesive to the rear side of acontinuous web of base material; releasably adhering the web of basematerial to a backing sheet; cutting a series of discrete base layersfrom the web of base material; removing the skeleton of the basematerial; and repeatedly removing a discrete water absorbent layer fromits backing sheet and adhering to a discrete base layer to form a seriesof laminate self-adhesive moisture control labels.